Bezos provides 1st BE-4 engine update in more than a year

Yesterday Jeff Bezos posted the first status update since last spring on the development of the BE-4 rocket engine by Blue Origin, posting one image and stating that the engine testing continues.

According to his post, the engine had just completed a full power test, and has been accumulating test time.

This update is very reassuring, especially following such a long period of silence, beginning in April 2018. Before that Blue Origin had provided somewhat regularly updates.

In reviewing my past posts, it appears that the updates more or less ceased once ULA announced its decision to use the BE-4 in its Vulcan rocket. I now suspect the earlier updates were aimed more at ULA than the public, and once the decision was made Blue Origin returned to its more traditional tight-lipped approach.

NASA/NOAA failure report for GOES-17: The government screwed up

A joint investigation by NASA and NOAA into the failure issues on the GOES-17 weather satellite, launched in March 2018, have determined that the problem with the Advanced Baseline Imager (ABI), the satellite’s main instrument, was caused by

a blockage in the instrument’s loop heat pipes, which transfer heat from the ABI electronics to its radiator. The blockage restricted the flow of coolant in the loop heat pipes, causing the ABI to overheat and reducing the sensitivity of infrared sensors.

You can read the short full report here [pdf].

My immediate thought in reading the press release above was: So a blockage caused the problem. What caused the blockage? Was it a design failure or a construction mistake? Or what? The answer to this question is even more critical in that the same issues have been identified in GOES-16, though not as serious.

Moreover, GOES-16 and GOES-17 are the first two satellites in a planned new weather constellation of four satellites. Knowing who or what caused this blockage prior to construction and launch of the two later satellites is critical.

I immediately downloaded the report and read it, thinking it would name the contractor and the cause of the blockage.

Nope. The report is remarkably vague about these details, which the report justifies as follows:

The report is NASA sensitive, but unclassified (SBU), because it contains company proprietary information. The report also contains information restricted by the International Traffic in Arms Regulations (ITAR) and/or the Export Administration Regulations (EAR). This summary report provides an overview of publicly releasable information contained in the full report.

In other words, this report is an abridged version of the full report, which is being kept classified because it contains both commercial proprietary information and information that if released would violate ITAR regulations designed to keep U.S. technology from reaching foreign hands.

What this public report does imply in its recommendations, in a remarkable vague way, is that the problem occurred because the government had demanded changes during construction that forced significant redesigns by the contractor, none of which were then given sufficient review.

Or to put it more bluntly, NOAA and NASA, the lead agencies in the GOES project, screwed up. They forced the contractor to make changes, probably very late in the process, resulting in inadequate review of those changes.

The recommendations put forth many suggestions to institute a more detailed review process, should late changes in the construction of the next two GOES satellites be required or demanded. Such recommendations however will only further delay and increase the costs for building those satellites. Since the entire constellation went overbudget significantly (from $7 billion initially to $11 billion), and has also been very late (see this GAO report [pdf]), this means that the next two satellites will be even later and more expensive.

For NASA and NOAA this is just fine, pumping more money into each agency. For the taxpayer it is terrible.

The whole process should be dumped. Give the job of building these satellites to the private sector, entirely. Get these agencies out of the construction business. The only contribution they are presently adding is more cost and delays, while also causing satellite failures.

Landowners in Scotland sign lease for spaceport

The new colonial movement: The landowners for a planned commercial spaceport in Sutherland, Scotland, have now signed a 75-year lease with the spaceport developers.

Construction of the project is anticipated to begin next year with the UK Space Agency (UKSA) providing a grant of £2.5million to HIE, as well as funding two launch companies who will use the facility once it is operational.

I highlight the word “UK”, which stands for the United Kingdom, because that word indicates another very big unstated obstacle to this spaceport. The UK as a whole has voted to leave the European Union. The population of Scotland however voted against that exit, and its leaders have indicated that they will not go along with the plans of the new British prime minister, Boris Johnson, to exit, deal or no deal. In fact, they have indicated that they would instead want to leave the United Kingdom in that case.

Should that happen, the future of this spaceport will be threatened. The deals that have made it possible have come from the UK space agency, a entity that Scotland would no longer belong should it leave the United Kingdom.

Chinese test microsat deorbits and crashes into Moon

The new colonial movement: A Chinese tiny smallsat, sent to lunar orbit to test the technology of such microsats, has been deorbited and allowed to crash into the far side of the Moon.

The micro satellite crashed into a predetermined area on the far side of the Moon at 10:20 p.m. on July 31 (Beijing Time), the center said Friday.

Weighing 47 kg, Longjiang-2 was sent into space on May 21, 2018, together with the Chang’e-4 lunar probe’s relay satellite “Queqiao,” and entered the lunar orbit four days later. It operated in orbit for 437 days, exceeding its one-year designed lifespan.

The development of the micro lunar orbiter explores a new low-cost mode of deep space exploration, said the center. The micro satellite carried an ultra-long-wave detector, developed by the National Space Science Center of the Chinese Academy of Sciences, aiming to conduct radio astronomical observation and study solar radiation.

China might be stealing a lot of the space technology it is using to make it a major space power, but it is also doing a fine job of refining and improving that technology. Its capability to do practically anything in space as well if not better than anyone else continues to grow.

And with their government using its space effort as a management test for determining the best individuals to promote into the government’s power structure, do not expect their space effort to wane anytime in the near future.

Parker data downloaded from first two orbits

The science team for the Parker Solar Probe has completed the download of all data gathered during the spacecraft’s first two solar orbits.

On May 6, 2019, just over a month after Parker Solar Probe completed its second solar encounter, the final transmission of 22 gigabytes of planned science data — collected during the first two encounters — was downlinked by the mission team at the Johns Hopkins Applied Physics Laboratory, or APL, in Laurel, Maryland.

This 22 GB is 50% more data than the team had estimated would be downlinked by this point in the mission — all because the spacecraft’s telecommunications system is performing better than pre-launch estimates. After characterizing the spacecraft’s operations during the commissioning phase, which began soon after launch, the Parker mission team determined that the telecom system could effectively deliver more downlink opportunities, helping the team maximize the download of science data.

The team has capitalized on the higher downlink rate, instructing Parker Solar Probe to record and send back extra science data gathered during its second solar encounter. This additional 25 GB of science data will be downlinked to Earth between July 24 and Aug. 15.

Don’t expect any immediate press conferences announcing results. It will take them time to analyze this batch, and they will probably want to do a few more orbits before coming to any conclusions.

Chandrayaan-2 successfully completes 4th orbit burn

The new colonial movement: India’s lunar orbiter/lander/rover Chandrayaan-2 today successfully completed its fourth engine burn, this time raising its orbital apogee to 89,472 kilometers (55,595 miles).

The next burn is scheduled for August 6, when the spacecraft’s orbit brings it back down to its perigee.

By September they expect to raise that apogee high enough so that it is within the Moon’s gravitational sphere of influence, when they will be able to put it the spacecraft into lunar orbit.

Bezos sells another $1.8 billion in Amazon stock

Capitalism in space? Jeff Bezos last night sold just under a million shares of his Amazon stock, earning in cash an estimated $1.8 billion.

Unlike a similar sale of stock by Bezos last April, there is no statement from Bezos about what he intends to use the money for. Then Bezos made it clear that he intended to periodically sell his stock to raise money for Blue Origin and its various space ventures. Today’s sale was the third since he said this, with total earnings from all three sales totaling about $4 billion, and all are likely aimed at funding that space company.

I might have increasing concerns about Blue Origin because of what appears to be a stalled rollout of New Shepard and New Glenn, but with deep pockets such as this, it would be surprising if the company fails to achieve its goals.

New NASA development contracts include refueling work by SpaceX

Capitalism in space: Yesterday NASA announced a bunch of partnership agreements with thirteen companies, where those companies will get NASA assistance at no cost to help them develop new engineering that would aid future solar system exploration.

The partnerships covered everything from helping small companies develop new space electronics, heat shields, and new types of thrusters to helping Blue Origin develop the technology for for landing on the Moon.

An article at Ars Technica today about this NASA announcement focused specifically on the SpaceX deal, mainly for its important political implications.

The partnership will have two different NASA agencies helping SpaceX develop the refueling technology it needs for Starship to reach Mars. The key is that this deal has NASA openly supporting technologies that are in direct competition with its own SLS rocket. When such research work was proposed back in 2010, it was opposed quite strongly by past agency officials as well as powerful politicians in Congress, for exactly that reason.

It was a contentious time in space policy, as the White House was pushing for more funding for new space companies—and new space ideas such as fuel-storage depots—while Congress wanted to keep NASA in the rocket-building business.

Eventually, Congress got the upper hand, putting NASA on track to build the large SLS rocket at a development cost of more than $2 billion a year. The rocket program mostly benefited the Alabama space center and was championed by Alabama State Senator Richard Shelby. The potential of in-space fuel storage and transfer threatened the SLS rocket because it would allow NASA to do some exploration missions with smaller and cheaper rockets. As one source explained at the time, “Senator Shelby called NASA and said if he hears one more word about propellant depots he’s going to cancel the Space Technology program.”

The line from other NASA officials was that as a technology, propellant depots were not ready for prime time. In 2011, former NASA Administrator Mike Griffin and current Executive Secretary of the National Space Council Scott Pace—both SLS advocates—wrote a withering criticism of the technology for Space News.

Now however the Trump administration is helping SpaceX develop refueling for Starship, which if successful will help make SLS irrelevant. This is more evidence that the Trump administration is laying the political groundwork that will allow it to shut SLS down, actions that were impossible in the political culture of Washington only two years ago.

This quote in the article is probably the most startling of all:

“Administrator Bridenstine is clearly executing on President’s Trump’s guidance to increase commercial public-private-partnerships at NASA,” Miller, now chief executive of UbiquitiLink, told Ars. “The game-changing technology that NASA has discovered is capitalism. This program proves NASA leadership has figured out the future is reusability mixed with commercial public-private-partnerships.” [emphasis mine]

Imagine that. An American government agency has learned that capitalism is the way to go. Will wonders never cease?

Update: See this related Ars Technica article: The SLS rocket may have curbed development of on-orbit refueling for a decade (Hat tip reader Calvin Dodge.)

Suborbital rocket company has launch failure

Capitalism in space: Gilmour Space Technologies, one of the numerous new rocket companies aimed at capturing the emerging smallsat market, experienced a launch failure on July 29 just prior to lift-off of its suborbital rocket.

At T-7 seconds to launch, the test rocket suffered an anomaly that resulted in the premature end of the mission. Initial investigations show that a pressure regulator in the oxidiser tank had failed to maintain the required pressure, and this caused the upper half of the rocket to be ejected as helium escaped.

On the positive side, there were no explosions due to the safe nature of hybrid rocket engines, and no observable damage to the engine. (The white plume seen here is steam.) Moreover, despite failure to launch, the team did successfully test Gilmour Space’s mobile launch platform and mission control centre, which had journeyed over 1,800 km to the test site.

It appears the failure was from a piece of equipment provided by an outside contractor.

LightSail-2 successfully raises its orbit using sunlight

Capitalism in space: By raising its orbit by the use of sunlight only, LightSail-2 has confirmed what an earlier Japanese solar sail Ikaros had demonstrated, that it is possible to use solar sails to travel in space.

Since unfurling the spacecraft’s silver solar sail last week, mission managers have been optimizing the way the spacecraft orients itself during solar sailing. After a few tweaks, LightSail 2 began raising its orbit around the Earth. In the past 4 days, the spacecraft has raised its orbital high point, or apogee, by about 2 kilometers. The perigee, or low point of its orbit, has dropped by a similar amount, which is consistent with pre-flight expectations for the effects of atmospheric drag on the spacecraft. The mission team has confirmed the apogee increase can only be attributed to solar sailing, meaning LightSail 2 has successfully completed its primary goal of demonstrating flight by light for CubeSats. [emphasis mine]

The highlighted text notes a secondary but possibly more important engineering achievement here. LightSail-2 was launched as a cubesat. It has now proven that such a cubesat can include a solar sail and use it for purposes of transportation.

Moreover, that this engineering test was funded entirely by private funds proves again that the government is not necessary for great things to be achieved.

They will continue to raise the spacecraft’s apogee for the next month, until the lowering of the perigee causes the spacecraft to get pulled out of orbit by the drag from the atmosphere. That second process will still take about a year.

iSpace plans eight launches in 2020

After its first successful orbital mission last week, China’s semi-private rocket company iSpace announced today that it hopes to complete eight launches in 2020.

Clients from Singapore, Italy, Spain, Hong Kong and Sri Lanka, as well as mainland customers, have already either signed up for a spot on iSpace’s rockets or expressed interest.

iSpace is open to both private and government clients. “It’s the same for us whether it’s a private or a state-owned company,” Vice President for Marketing and Communications Yao Bowen said.

The price tag to launch a rocket is 4.5 million euros ($5 million), Yao added.

This launch price is just under what Rocket Lab has been charging, $6 million, and is clearly designed to take business from them. It is however higher than what Vector says it will charge, $4 million, should that company ever get its rocket off the ground.

The article also notes the investment capital raised by iSpace, totaling just over $100 million. This does make this company appear a private company, but don’t believe it. Its existence is very much tied to and supervised by the Chinese government.

A bullseye on Mars

Layered crater at equator
Click for full image.

Cool image time! In researching my piece last week on the glaciers of Mars I had wanted to include a picture of a typical concentric glacier-filled crater, the most widespread glacial feature on the Martian surface, found in a band at latitudes between 30 and 60 degrees. (You can see the example I found at the link above, near the end of the article.)

To find that picture I searched the Mars Reconnaissance Orbiter (MRO) archive. Among the images I found was a captioned image taken very early in MRO’s mission showing a crater with concentric rings very similar to the concentric glacial-filled craters. The image at the right is that crater, the image reduced and cropped to post here. As described in that caption,
» Read more

Europe completes 1st rollout of Ariane 6 mobile launch gantry

The mobile launch gantry that Europe will use for its new Ariane 6 rocket successfully completed its first rollout tests last week.

This gantry is the equivalent of NASA’s VAB building. Within this gantry they will assemble Ariane 6 vertically, then roll the gantry back for launch.

Assembling a rocket vertically I think is more costly, but it also makes it possible for the rocket to launch payloads that must be installed in this manner. Thus, Ariane 6 will have this selling point over rockets like the Falcon 9 and Falcon Heavy, which are assembled horizontally.

Private lunar landing company backs out of NASA contract

Capitalism in space: The commercial lunar landing company, OrbitBeyond, has told NASA that it cannot fulfill its $97 million contract, only two months after that contract was announced.

NASA announced July 29 that OrbitBeyond informed the agency that “internal corporate challenges” will prevent it from carrying out a task order that NASA awarded the company May 31 as part of its Commercial Lunar Payload Services (CLPS) program. The company asked to be released from that contract, and NASA agreed.

NASA didn’t elaborate on what specific issues caused OrbitBeyond to scrap its contract with NASA, and the company didn’t immediately respond to a request for comment. At the May 31 event where NASA announced the contracts, Siba Padhi, chief executive of OrbitBeyond, said the company was still in the process of closing a round of funding. The company has not subsequently announced a funding round.

Considering its receipt of a $97 million NASA contract, it would be very puzzlingly for the company to be unable to obtain further investment capital. If anything, that contract should have encouraged funding. If the lack of funding is the cause of this termination then it also suggests the company had other problems.

This leaves NASA with two private lunar lander companies. I expect NASA will look to award the contract to a third company. The company Firefly and its team of Israeli Beresheet engineers comes immediately to mind.

Chandrayaan-2 completes third orbit maneuver

Chandrayaan-2 has completed its third engine burn to raise the apogee of its orbit to 71K.

The next burn is set for August 2, when the spacecraft returns to its orbital low point, the perigee. As it raises its orbit each time the time between burns gets extended because the orbit gets longer. By September however the apogee will put the spacecraft in the Moon’s gravitational field of influence, and when Chandrayaan-2 reaches that apogee engineers will then fire its engines again to slow it down and enter lunar orbit.

Russia launches communications satellite

Using its Soyuz rocket the Russians today launched a satellite aimed at providing communications to Russia itself.

The satellite, while apparently providing civilian communications services, was a Russian government project. It is not commercial as we would define it in the west.

The leaders in the 2019 launch race:

11 China
10 Russia
9 SpaceX
5 Europe (Arianespace)
4 India

The U.S. continues to lead China 15 to 11 in the national rankings. At the moment it also looks like Russia has a chance to top 20 launches in 2019, which would make this its best launch year since 2015. This suggests that they have finally begun to recover from the discovery in 2017 that an engine contractor was using substandard welding materials to pocket some extra cash, thus causing many launch failures.

TESS finds the first two mini-Neptune exoplanets

In discovering three candidate exoplanets orbiting a nearby red dwarf star, the space telescope TESS has found the first two that are sized somewhere between the rocky Earth-sized planets and the larger Neptune-sized gas giants.

The innermost planet, TOI 270 b, is likely a rocky world about 25% larger than Earth. It orbits the star every 3.4 days at a distance about 13 times closer than Mercury orbits the Sun. Based on statistical studies of known exoplanets of similar size, the science team estimates TOI 270 b has a mass around 1.9 times greater than Earth’s. Due to its proximity to the star, planet b is an oven-hot world. Its equilibrium temperature — that is, the temperature based only on energy it receives from the star, which ignores additional warming effects from a possible atmosphere — is around 490 degrees Fahrenheit (254 degrees Celsius).

The other two planets, TOI 270 c and d, are, respectively, 2.4 and 2.1 times larger than Earth and orbit the star every 5.7 and 11.4 days. Although only about half its size, both may be similar to Neptune in our solar system, with compositions dominated by gases rather than rock, and they likely weigh around 7 and 5 times Earth’s mass, respectively.

All of the planets are expected to be tidally locked to the star, which means they only rotate once every orbit and keep the same side facing the star at all times, just as the Moon does in its orbit around Earth.

Planet c and d might best be described as mini-Neptunes, a type of planet not seen in our own solar system. The researchers hope further exploration of TOI 270 may help explain how two of these mini-Neptunes formed alongside a nearly Earth-size world.

The star is only 73 light years away.

Need I say that our level of knowledge about solar system formation is tiny at this point, and that any models any theorist creates should merely be seen as scratchpad first approximations, useful only in guiding future research and not to be taken too seriously.

Japanese private smallsat rocket company launch failure

Capitlism in space: Interstellar Technologies, a Japanese private smallsat rocket company, experienced on July 27 its third suborbital launch failure in four attempts.

The vehicle only reached an altitude of 13 kilometers following the launch at 4:20 p.m., falling into the sea some 9 kilometers (about 5.5. miles) offshore from Taiki, Hokkaido, its test site, Interstellar Technologies said. The rocket is the same model as Momo-3, measuring about 10 meters long, 50 centimeters in diameter and weighing 1 ton.

After failed attempts in 2017 and 2018, the startup finally found success with its third launch in May, with the rocket reaching an altitude of around 113 km before falling into the Pacific Ocean.

The failure occurred when an onboard computer detected something wrong and shut the engine down.

China tests controlled flight for returning first stage

Chinese news sources today confirmed that during its last launch on July 26, they tested the use of grid fins (essentially copied from SpaceX’s Falcon 9) to control the return flight of the first stage of their Long March 2C rocket.

The success of the test is of great significance for improving China’s inland rocket landing safety, minimizing the inconvenience to the local people, as well as promoting the follow-up development of carrier rockets’ controllable recovery, soft landing and reuse, according to He Wei, an official with the CASC.

“The swinging grid fins were used to control the rocket debris’ direction and attitude, much like the wings of the debris,” said Cui Zhaoyun, the deputy chief designer of Long March-2C rocket. The landing site control of large and medium rockets is much more difficult than that of small rockets, he added.

For almost forty years China has allowed these first stages to crash, sometimes very close to villages and habitable areas. Now, inspired by what freedom and U.S. innovation has accomplished, they have finally begun the process of figuring out how to land these stages vertically. Since their propellants are very toxic, it is not clear however whether they will be able to reuse them should they succeed in landing them undamaged.

Golfing with boulders on the Moon

Boulder tracks on the Moon
Click for full resolution image.

Cool image time! The Lunar Reconnaissance Orbiter team this week released a beautiful image of boulder tracks rolling down the inside slope of 85-mile-wided Antoniadi crater on the far side of the Moon. The image above, cropped, reduced, and annotated to post here, shows these tracks.

The most obvious track is cool because the boulder almost made, as the scientists note, “a hole-in-one.”

Running from the outcrops to the rim of the partially buried crater is a track etched by a rolling boulder bigger than a bus. Perhaps a moonquake shook it loose. The boulder bounced and rolled toward the partially buried crater, plowing a path that is still visible through the loose material of the slope. When it reached the rim of the partially erased crater, its path curved and it slowed to a stop.

…Had it rolled just 75 meters more, the boulder might have plopped neatly into a 30-meter-diameter young impact crater on the floor of the partially erased crater.

The arrows I have added indicate two more less obvious boulder tracks. If you click on the full resolution image and zoom in you can also see another series of impressions in the middle of the photograph that look like a dotted line, suggesting they were left by a boulder bouncing down the slope.

The scattered of boulders in the floor of the small crater all likely came from the top of the big crater’s rim, which I show in the wider image below.

Wider image showing entire crater slope

The box indicates the location of the image above.

While many things over the eons could caused these boulders to roll (moonquakes, erosion from the solar wind, other nearby impacts), a close look at the ground surrounding them does not show tracks emanating from most, suggesting they have been there a very long time, long enough for the surface reworking caused by the solar wind to have smoothed those tracks out.

The Moon is airless and mostly dead. The solar wind is incredibly weak. Any changes caused by it will take a lot of time. Consider the time required to smooth out those tracks. The mind boggles.

NASA to do full engine test of SLS first stage

NASA confirmed yesterday that it will do a full engine test of its SLS first stage, what it calls the Green Run test.

This decision makes sense. SpaceX for example routinely does a static fire test of its first stages before every flight. NASA however had hesitated doing this test because it will likely force a delay in the first launch of SLS. Unlike a commercial company like SpaceX, NASA is incapable of doing this test and then proceeding to flight quickly, mostly because the size of SLS (it is very large) and its design (very cumbersome) makes such quick action difficult.

This decision however means that it is almost certain that SLS’s first unmanned test launch cannot happen in 2020. For NASA to make Trump’s commitment to fly a lunar landing by 2024 means that NASA must compress SLS’s schedule to one flight per year. First the unmanned test flight would occur, probably in 2021. Then the first manned test flight around the Moon would follow, in 2022 or 2023. Finally the landing mission would take place in 2024.

Can NASA do this? I have many doubts. The agency’s biggest obstacle would be getting their lunar lander built in time, which by the way is not yet even designed. This isn’t the only problem. NASA for years has said that they will need from one to three years between SLS flights. This schedule demands more from them.

Meanwhile, there is a good possibility that SpaceX will beat them to the Moon. If that happens, then expect SLS to die, either before or after its first or second flight.

Starhopper has hopped

Capitalism in space: SpaceX last night successfully completed the first untethered flight of its Starship/Super Heavy prototype dubbed Starhopper.

This hop attempted and flew about 65 feet. They hope to do next flight, planned to be about ten times higher, in a week or two, according to a Musk tweet.

Below the fold is video of the hop. You can’t see much as the viewing angle is ground level, it is night, and the engine flames obscure things. Expect better footage from future hops.
» Read more

SpaceX launches used Dragon to ISS with used Falcon 9

Capitalism in space: SpaceX today successfully used a Falcon 9 rocket to launch a Dragon freighter to ISS.

The Dragon is making its third flight to ISS. The first stage, which landed successfully, was making its second flight, and will likely be used on the next Dragon cargo mission.

Video of the launch and 1st stage landing is below the fold. The launch is at about 15 minutes. The first stage landing is one of the most spectacular yet.

The leaders in the 2019 launch race:

10 China
9 Russia
9 SpaceX
5 Europe (Arianespace)
4 India

The U.S. now leads China 15-10 in the national rankings.
» Read more

The state of water on the Moon

Link here. The article describes new research that suggests the ice thought to exist in the Moon’s permanently shadowed polar craters is constantly being reworked, with some being leached away as other processes (comets, solar wind) replenish the losses.

They also theorize that this process might be making it easier to reach that water.

For forthcoming science and exploration, the scattering of water particles could be great news. It means astronauts may need not to subject themselves and their instruments to the harsh environment of shadowed crater floors in order to find water-rich soil — they could just find it in sunny regions nearby. “This research is telling us that meteoroids are doing some of the work for us and transporting material from the coldest places to some of the boundary regions where astronauts can access it with a solar-powered rover,” Hurley said.

To put it mildly, there is a lot of uncertainty about this last conclusion.

Chandayaan-2 completes first orbit burn

India’s lunar orbiter/lander/rover Chandrayaan-2 yesterday completed its first orbital engine burn, raising its apogee, the high point in its orbit, 6,000 kilometers to about 51,000.

This boost meant that Isro scientists have to perform one less manoeuvre in the Earth orbit than what was planned earlier. According to the path chalked out for Chandrayaan-2 before the launch, the on-board propulsion systems were to be fired six times in Earth orbit – five times to raise the apogee and once to raise the perigee. Now, only four more “burns”, or firing of the propulsion system, will be needed on July 26 and 29, and August 2 and 6, to reach the final orbit of 233.2 x 143,953km.

…With a final boost on On August 14, Chandrayaan-2 will escape Earth’s orbit and begin its seven-day journey towards the moon. The spacecraft is scheduled to reach the moon orbit on August 20.

Once in lunar orbit they plan four more burns to lower the spacecraft to a 100 kilometer circular orbit, where the lander/rover will release and begin their own lowering process aimed for a September 7 landing.

End coming for twin Van Allen spacecraft

Engineers at the Applied Physics Lab in Maryland on July 19 turned off one of the two Van Allen probes, with the second probe expected to receive a similar command later this year.

As expected, following final de-orbit maneuvers in February of this year, the spacecraft has used its remaining propellant to keep its solar panels pointed at the Sun and is now out of fuel. Since it depends on the Sun to provide power to the instruments, and can no longer orient itself to acquire power, the spacecraft has been turned off. The spacecraft is in a stable, circular orbit around Earth and, in about 15 years, will re-enter the atmosphere and burn up safely. The de-orbit maneuvers in February were designed to ensure this would happen and prevent the spacecraft from becoming “space junk” in orbit.

The other Van Allen Probes spacecraft, spacecraft A, is expected to operate normally until early September.

Both spacecraft functioned five years longer than expected, and during that time discovered that there are three Van Allen belts, not two as previously thought.

1 251 252 253 254 255 484