Posted October 28, 2010 10:14 AM
By David Todd
U.S. SENATORS THINK THEY ARE ROCKET SCIENTISTS AS OTHERS MOURN ALTAIR LUNAR LANDER
After much negotiation between the U.S. Senate and House of Representatives, the NASA authorization bill was passed in late September and has now been signed by President Obama.
The new bill adds one more space shuttle flight and authorises the continued development of the Orion spacecraft and of a heavy-lift launch vehicle (HLV) to be used for missions to the asteroids and eventually to Mars. The bill also allows US$1.3 billion in funding to encourage commercial manned spaceflight to Low Earth Orbit. Note that an Authorisation Bill precedes a formal Appropriations Bill when the money is actually formally doled out.
End of the line for the Altair lunar lander. While U.S. astronauts will be able to make flybys of the moon, without Altair or similar landing craft, there will be no manned NASA lunar landings during the next twenty years. Courtesy: NASA
The S.3729 Authorisation Bill allocates just over US$19 billion annually for NASA for the next three years. Significantly, the Bill defines that the heavy lift rocket should be derived, where practical, from the Space Shuttle and that its payload requirement should “provide a scalable capability of lifting payloads of at least 130 metric tons into low Earth orbit on a single launch vehicle with an upper stage in preparation for transit for missions beyond low-Earth orbit.” This effectively ends the chances of the ‘sidemount’ close derivative of the Space Shuttle whose payload is projected to be circa 80-90 metric tons. This leaves the more expensive but more powerful and more evolvable ‘in line’ Shuttle derivative HLV. Operations to the International Space Station are to continue until 2020.
No money has been allocated to develop any kind of lunar lander and Project Constellation’s Altair lunar lander is effectively cancelled. This has caused much sadness and regret to those in NASA who wanted the administration to return astronauts to the moon as soon as possible. This was especially in light of the recent discoveries from observations of the LCROSS mission lunar collision that extractable quantities of water, volatiles and metallic elements exists at the lunar South poles.
There is also concern in the administration that the U.S. Senate itself is taking on the mantle of a rocket design bureau. While the senators were rebuked by some for ‘acting like rocket scientists’ despite having no expertise in that area, a more measured rebuttal came from Robert Braun, NASA's chief technologist. He is reported in the Orlando Sentinel as saying that NASA will refuse to be bound entirely by the technical elements of the bill, noting that the administration would choose the rocket design and size that was right for it. Apart from disagreements in NASA over what size of rocket they need, there are still supporters of using a LOX/kerosene first stage instead of a shuttle-based LOX/Liquid Hydrogen one.
Comment: The recent NASA Human Exploration Framework Team (HEFT) study came down firmly in favour of an inline option and this may have influenced the Senate. However, by going for the more complicated if more capable ‘in line’ heavy lift rocket instead of the more closely related Shuttle-derivative 'Sidemount' design, this will increase the costs dramatically. The Shuttle fuel tank will require significant structural modifications while the whole launch site will now have to be extensively and expensively revised. Worse, this means that there will not be enough money to build a manned lunar lander. As such, there is a big danger here of having a working manned launch system but no place to go.
Asteroid spaceflight is a sensible aim but only after some easier-to-do moon landing flights first. As such, our view is that the cheaper ‘Sidemount’ design of heavy lift rocket is a better and cheaper option at least as an interim lifter. By choosing it, this could then release enough money for a cut-down Altair landing craft to be built. This interim option would also allow lunar and possibly even asteroid missions to be flown and buys time to get a super-heavy lift in-line rocket right. This will be needed for Mars operations and should really carry a payload of more than 200 metric tons to low Earth orbit – a performance that no Shuttle based vehicle is going to be able to do.
There is also a political and national pride dimension. With the confirmation of the indefinite delay to NASA’s Altair-style lunar lander, this puts Russia and China forward as being those nations most likely to return an astronaut to the moon - a fact which U.S. citizens might find difficult to swallow.
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