Asteroid Retrieval Feasibility Study

 future projects, spacecraft  No Responses »
Jan 092013
 

An interesting study written for the Keck Institute of Space Studies (at JPL) has been published describing how to go about grabbing a near-Earth asteroid of about 7 meters diameter (250 to 1000 metric tons mass), and drag it into Lunar orbit.

The spacecraft is proposed to be an unmanned vehicle with Hall effect thrusters (a type of ion engine), using large solar panels to generate the electricity needed. The writers of the study suggest that a 500-ton asteroid could be transported to high lunar orbit by 2025. The small asteroid could then be used as a base of operations/source of raw materials for manned missions to the Moon and beyond.

The capture mechanism would be fairly simple: a large inflatable bag. The spacecraft would simply envelope the asteroid (after matching rotation), cinch in the bag, and slowly shove the rock to the Moon. Due to the exceedingly low thrust/weight that the loaded spacecraft would have, lunar orbit capture would be a complex dance.

The spacecraft would have an initial mass of 18,000 kilograms and would be launched by an Atlas V or similar booster. The 40 kilowatt solar-electric propulsion system would have an impressive Isp of 3,000 seconds, but a vanishingly low thrust (which does not seem to have been given in the study). 12 metric tons of the 18 would be xenon propellant for the thrusters.

The mission would be a very long duration one. After being delivered to low Earth orbit, 2.2 years would be required to spiral out to the moon. A gravity assist would be used to boost the craft towards the target asteroid; 1.7 years would be needed for the cruise. After rendezvous, 90 days would be needed to precisely match orbits, precisely match rotation, capture the asteroid and de-tumble. Another 2 to 6 years would be needed to transit to lunar orbit. Total: 6 to 10 years. One example mission involves launch on 4/28/2018 and return with asteroid 2008 HU4 (assumed to be 7 m diameter, 1300 tons mass) on 4/26/2026.

 Posted by at 2:32 pm

The ISS as it might have been…

 space station, spacecraft  2 Responses »
Dec 222012
 

Before the International Space Station was the International Space Station, it was originally Space Station Freedom. This was in the heady days of Reagan and anti-Soviet technological developments such as the Strategic Defense Initiative, the latter half of the 1980s. The Station as then envisioned would have been an all-American Station (although the Europeans and Japanese could tag along with modules of their own), designed to fulfill NASA and DoD requirements, rather than State Department requirements like the ISS. As with SDI, it was grandiose and of course not to be.

The Station as planned circa 1987 could be grown into a “dual keel” design quite a bit larger than the ISS as actually built. It would feature numerous solar power plants, both photovoltaic and solar dynamic. It was planned that a satellite servicing center would be fitted, allowing, as the name suggests, for the repair and refitting of satellites. In order to permit that, a space tug (OMV – Orbital Maneuvering Vehicle) would also need developing that could retrieve the satellites, then return them to their orbits.

Sadly, the Station was always a political football. The cost was immense, and with the collapse of the Soviet Union, the military applications of the Station (not least of which would have been the propaganda value of a Real American Space Station) ceased to seem relevant. Plans were scaled back, it was transformed into an International effort in order to spread cost  and curry political favor, and the ISS end result is but a shadow of what was originally planned.

 Posted by at 10:27 am

SLS

 future projects, launch vehicles, rockets, spacecraft  No Responses »
Nov 242012
 

A chart from a NASA briefing from May of this year giving a quick look at three planned configurations of the Space Launch System which some/many in NASA hope to get built and flown in the coming years.

When transitioning from the Block 1 to Block 1A configurations, the plan is to replace the Shuttle-derived five segment solid rocket boosters with all-new advanced boosters, either liquid or solid. But history has shown that if what you’ve got *now* more or less works, replacing it with an expensive new rocket is a somewhat politically dubious prospect.

 Posted by at 11:27 pm

Space… craft? Station?

 research, space station, spacecraft  1 Response »
Nov 172012
 

A Boeing (or possibly North American Aviation) artists concept of what appears to be a space station, but may be an interplanetary spacecraft. While overall it appears to be a Saturn V derived space station (using, apparently, the S-IVb tanks as a basis), on the right there appears to be a bay holding several Viking-style entry capsules. Numerous interplanetary spacecraft designs of the 1960’s had these. The capsules would hold not people, but unmanned landers and rovers. The relatively small size of the solar panels might indicate that this craft was designed for a mission to Venus; the apparent lack of much of a propulsion system might indicate that this was a flyby mission rather than a capture-and-orbit mission.

Note also the centrifuge that takes up the second deck from the “bottom.”

 Posted by at 1:00 pm
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