Comments on: Japan unveils new small rocket

By: Edward

Edward — Wed, 11 Jan 2017 23:13:20 +0000

Alex and LocalFluff,
The Solar Astrophysics Lab that I worked in used to send an x-ray telescope on sounding rockets to take x-ray photographs of the Sun. As one of you mentioned, this gave only a snapshot of what was happening on the Sun, and after several years of flights, the lab lost the telescope when the parachute failed to properly open — the telescope was damaged beyond what the customer was willing to pay to fix. That lab now puts x-ray telescopes onto satellites, such as the recent set of GOES satellites. This allows for more photographs per day and results in “movies” of the action taking place on the Sun.

Sounding rockets are still used in the US today, and are most often launched from Wallops Island, Virginia and from White Sands, New Mexico. Other countries also use sounding rockets. Sounding rockets and their payloads don’t seem to get much press, as they aren’t as exciting as Rosetta, Curiosity, Hubble, or ISS, but they still contribute to our understanding of the Earth and the universe.

LocalFluff,
If you have an entrepreneurial spirit, you may want to look into your Dragon-Falcon idea. Without the expendable upper stage or an expendable service module, you may get a cheap enough and long enough exposure to zero-g for seven passengers to make it worth the price. I wouldn’t worry too much about the reentry speed, as reentry speed from orbit (which has an upper stage boost) is 5 km/s. Reentry should still be relatively safe, no matter how exciting you advertise it to be.

By: Alex

Alex — Wed, 11 Jan 2017 18:19:03 +0000

@LocalFluff: I just read that SS-520 as sounding rocket propelled a payload (mass?) to an altitude of 1,108 km.

http://www.astronautix.com/s/ss-520.html

By: LocalFluff

LocalFluff — Wed, 11 Jan 2017 17:26:04 +0000

“Tourists” launched with a F9+Dragon in a sounding rocket configuration might be a more exhilarating and cheaper trip than what Virgin Galactic and other sub-orbitals are offering. More expensive for sure, but more realistic in near term. I learn that reentry speed might be high, 3-4 km/s, but that could be marketed as part of the excitement! (Payment in advance, ehum)

By: Alex

Alex — Wed, 11 Jan 2017 17:16:07 +0000

@LocalFluff: Clearly, sounding rockets’ payload may have some advantages compared to satellites. However, higher apogee means also higher reentry speed (up to 3.5 km/s for Maxus), combined with a very steep path, high thermal loads. I have to correct myself single stage Maxus sounding rocket (using a Castor IVB- booster) has typical reached 700 km altitude and 14 min weigtlessness. I try to remember about origin of my remembered 2000 km. It might come another multi-stage sounding rocket project.

https://en.wikipedia.org/wiki/Maxus_(rocket)

By: LocalFluff

LocalFluff — Wed, 11 Jan 2017 13:22:01 +0000

@Alex
I will have to take a closer look at sounding rockets. I thought they barely escaped the atmosphere. They sound(!) more interesting than sub-orbital flights. An hour or an hour and a half in space seems to be very achievable, and plenty for some kinds of astronomy. Transient astronomy is ion the rise, but most stuff up there doesn’t change much and there’s no need for more than one single observation with the same instrument. Observation of wavelengths that the atmosphere blocks.

I suppose that the mass any orbital launcher can launch straight up is a multiple of its orbital capacity, not having to accelerate the payload to 8 km/s. Larger mass means cheaper and more reliable spacecraft design. And very much simplified compared to a long-term orbital payload. No need for any propulsion system for station keeping. The power system could consist of a battery. Radiation hardening wouldn’t be needed, allowing for use of the latest cheapest fastest electronics on board. It wouldn’t even need any communication but the data could be stored physically and recovered after landing. The payload (except the memory chip) wouldn’t need to be soft landed after its only use, alternatively one could reuse the same payload in different configurations, like NASA’s airborne SOFIA IR telescope.

A Falcon 9 first stage should be easier to land when it isn’t accelerated horizontally. If an F9 can bring 20+ tons to orbit, it could maybe bring 50 tons to an hour and a half in space as a sounding rocket? And all of it useful payload since it would need no upper stage engine or fuel. Just use a mirror as large as fits the fairings, mass isn’t a problem!

By: Alex

Alex — Wed, 11 Jan 2017 12:37:10 +0000

Correction: SS-520 instead of 33-250 launcher

By: Alex

Alex — Wed, 11 Jan 2017 12:36:09 +0000

@Mr. Zimmerman: Chinese “small” launcher (Kuaizhou 1A) has a lift-off mass of about 30 t and 250 kg payload. The launch mass is one order of magnitude larger as 33-520 micro-launcher (about 2.6 metric tons) and therefore a different category of launcher. Its payload is even two orders of magnitude larger, which demonstrates the small efficiency of SS-520 launcher, which may have some reserves.

By: LocalFluff

LocalFluff — Wed, 11 Jan 2017 08:27:16 +0000

Here are a couple of well informed reliable sources I’ve found:
http://space.skyrocket.de/doc_lau/ss-520.htm
https://www.nasaspaceflight.com/2017/01/jaxa-ss-520-rocket-tricom-1-launch/

As I commented on its delay in your later post, this might be the most expensive launch ever. one MILLION dollar per kilogram!
https://www.youtube.com/watch?v=l91ISfcuzDw

By: Robert Zimmerman

Robert Zimmerman — Tue, 10 Jan 2017 22:12:52 +0000

In reply to Alex. Alex: Most interesting. Do you have sources where I could compare the Japanese small rocket with the new Chinese one that launched this week?

By: Alex

Alex — Tue, 10 Jan 2017 21:48:41 +0000

Mr. Zimmerman: This 3-stage rocket is not completely new, actually an existing two-stage sounding rocket was equipped with a third stage to achieve orbital velocity. However, BTW, just for the record, Mr. Zimmerman: It is the smallest launcher ever launched!!! Only 3.5 tons lift-off mass!