Original URL: http://www.theregister.co.uk/2010/12/16/orbital_sciences_spaceplane/

New spaceplane proposed for NASA station crew contract

Pocket shuttle offers astronauts backdoor entry

By Lewis Page

Posted in Science, 16th December 2010 13:07 GMT

Another candidate to replace NASA's space shuttle in the task of carrying astronauts to and from the International Space Station (ISS) has come forward. Unlike most of the other contenders, it is a winged space plane rather than a capsule.

The proposed CCDev spaceplane from Orbital Sciences pictured during ISS operations. Credit: OSC

In space, nobody can hear your ship going 'beep beep beep'

Orbital Sciences Corporation, an American firm which makes satellites and launch rockets, yesterday announced its proposal for NASA's Commercial Crew Development (CCDev) plan, under which the space agency will hire private companies to provide passage to and from the ISS. CCDev is a new way of doing business for NASA, which formerly bought rockets, spacecraft etc from contractors but operated them itself.

The Orbital proposal has several important differences from today's Shuttles. The "blended lifting body" spaceplane doesn't have its own engines like a Shuttle orbiter: rather it will travel into space atop a conventional throwaway rocket stack. It will carry just four astronauts, and will dock with the space station using a hatch situated at the rear, where the Shuttle has its engines. After departing from ISS, the Orbital craft will descend to a runway landing.

Most other contenders for CCDev - Elon Musk's Falcon 9 rocket and Dragon spacecraft, Boeing's CST-100 and the Orion craft which survives from NASA's cancelled Constellation programme - are capsules, intended to re-enter the atmosphere without much alteration to their orbital track and set down by parachute. The Shuttle's spotty safety record has made many designers wary of spaceplanes.

That said, there is another winged craft contending to be a CCDev astronaut lifter, the "Dream Chaser" design submitted by Sierra Nevada Corporation. Orbital's new offering is somewhat smaller, with four seats as compared to six, and appears to have more wing area - hinting at greater "cross range" capabilities.

Rocket to be provided by the usual suspects

Concept pic of the proposed CCDev spaceplane. Credit: OSC

Basically a very fancy glider

"Cross range" refers to a winged craft's ability to bend its course away from its orbital track as it re-enters. Famously the Shuttle was designed to offer good cross-range capability at the insistence of the US military, who planned cunning, secretive single-orbit missions from their space base in California. Without cross-range ability, a returning shuttle would find that the planet had turned beneath it and come down in the Pacific after a one-orbit hop.

In the end the military missions were never flown, causing heartache for those who considered that the Shuttle orbiter could have been a more capable spacecraft without the requirement for good cross-range and the resultant large, heavy heatshielded wings. There were those who had argued instead for a "lifting body" or "stub wing" design which would have offered less cross-range but more payload.

Orbital's description of their spaceplane as a "blended lifting body" suggests that cross range wasn't a big priority in the design, certainly.

Another item to note with the Orbital proposal is that this is not the same sort of effort as Elon Musk's SpaceX push to get Falcon 9 and Dragon into service, in which a new firm is producing new designs from scratch. Orbital is leading a consortium of established space heavyweights for this proposal, which would see the plane built largely by Northrop and Thales Alenia Space and the launch rockets provided by United Launch Alliance (the dominant rocketry consortium set up by Boeing and Lockheed).

This bid, then, is the established space industry moving in on NASA's CCDev cash, which many had thought/hoped would go primarily to so-called "new space" firms developing innovative equipment. Jeff Bezos' Blue Origin venture has in fact received some CCDev money, but it has no plans at present for an orbital vehicle.

The rival "Dream Chaser" would also lift atop a United Launch Alliance stack, and the Sierra Nevada six-seat spaceplane is also based on an old NASA design (as is the new Orbital one, for that matter).

The question is, does NASA want to go with existing, well proven but expensive kit - and see one or more of its old spaceplane designs fly again - or would it rather go for Elon Musk's new all-kerosene rockets and supposedly accurately-landable Dragon capsule?

Even when NASA chooses a new heavy lift rocket in 2015, this will probably not be rated to carry a crew - the Constellation Ares V was not, after all. The new big lifter will hoist the asteroid-mission and Mars ships of the 2020s into space, but their crews will probably ride up to rendezvous in orbit aboard whatever comes out of the CCDev effort.

Orbital's new plane, the Dream Chaser, Dragon and the others are all vying not just to carry space station crews - but perhaps to carry the first human on Mars for the first part of his or her journey. ®