Tag: Eris

Australian rocket startup Gilmour preps for first test launch

9:23 am

Gilmour Space Technologies, a new Australian rocket startup, is now targeting April for the first test launch of its three-stage Eris rocket from a launchpad on the northeast coast of Australia.

Standing 25 m (82 ft) high, [Eris] has a first-stage diameter of 2 m (6.6 ft), and a second-stage diameter of 1.5 m (4.9 ft), and it’s designed to take a payload mass up to 305 kg (672 lb) up as high as 500 km (311 miles) for delivery to sun-synchronous or equatorial orbits. The Eris will be powered by five of Gilmour’s own Sirius rocket engines. This is a hybrid engine, meaning it uses a liquid oxidizer but a solid fuel. In a final bench test to destruction, it generated 115 kilonewtons (25,850 lbf) and burned for more than 90 seconds before exploding.

More information here.

Leave a comment

The size of Pluto pinned down

12:59 pm

Data from New Horizons has allowed scientists to more firmly determine, for the first time, Pluto’s precise size.

Mission scientists have found Pluto to be 1,473 miles (2,370 kilometers) in diameter, somewhat larger than many prior estimates. Images acquired with the Long Range Reconnaissance Imager (LORRI) were used to make this determination. This result confirms what was already suspected: Pluto is larger than all other known solar system objects beyond the orbit of Neptune. “The size of Pluto has been debated since its discovery in 1930. We are excited to finally lay this question to rest,” said mission scientist Bill McKinnon, Washington University, St. Louis.

Pluto’s newly estimated size means that its density is slightly lower than previously thought, and the fraction of ice in its interior is slightly higher. Also, the lowest layer of Pluto’s atmosphere, called the troposphere, is shallower than previously believed.

This means that Pluto is at this moment the largest Kuiper Belt object so far known, bigger than Eris, the Kuiper Belt planet discovered in 2005 that had been thought to be bigger than Pluto and whose existence was used by some to demote Pluto’s status as a planet.

I say, they are both planets, because they are both heavy enough for gravity to have forced them to become spherical.

6 comments