Suborbital experiments worth the cost

Yesterday, some commercial space news made the NY Times (“Space Tourism: One Giant Leap for Researchers” and Wired (“Scientists Buy Rocket Rides to Suborbital Space”). Science institutes are buying tickets on suborbital flights to run experiments:

[The Southwest Research Institute] announced Monday that it has signed a contract and paid the deposit to send two of its scientists up in Virgins SpaceShipTwo vehicle. Southwest also intends to buy six more seats $1.6 million in tickets over all.
That follows an announcement on Thursday that Southwest is buying six seats from another suborbital company, XCOR Aerospace of Mojave, Calif., which has been charging $95,000 a seat for tourists. XCORs Lynx space plane carries just two people the pilot and the paying passenger so each flight will carry an experiment and an institute scientist.

My immediate reaction was to think of a post on Research Remix that listed the number of papers produced per $100,000 in grant money for different granting agencies (“Rough estimate of papers per dollar”). Basically, the wider the net, the fewer the papers, with major funded university research in the U.S. and Canada yielding fewer than one paper per $100,000 according to many estimates.

I might have dismissed such estimates as unrealistic several years ago. But I see where they’re coming from – don’t forget indirect costs, which pad all federal grants, and consider the very high expense of some fields of research. Personally, I can’t imagine how I could spend that much on a paper, even if I printed it on graphene. But there it is.

Now, if you’re going to spend $100,000 on the average paper, it does make a sort of sense to spend that much on suborbital microgravity access.

But in none of the reports have I seen the comparison to the expense of the usual atmospheric parabolic flights – the “Vomit Comet” and its international equivalents. Commercial access to these flights can be had for less than $4000 per passenger. Granted, some experiments (the over-the-atmosphere UV sensing, for example) can’t be done in the atmosphere. But I’m really skeptical that there’s a compelling value in a 4-minute suborbital experiment to justify that cost.

UPDATE (2011-03-01): I have an e-mail response from Lee Valentine, on the board of directors of XCOR Aerospace:

Dear Prof. Hawks,
Your website is wonderful. It gives me a great deal of enjoyment.
I have to disagree, however, with your take on suborbital research. There is a very big difference between 20 seconds of microgravity and 4 min. of microgravity. For many experiments, for which gravitational acceleration is the primary consideration, it is a huge difference. Of course, as I'm sure you recognize, parabolic flights at 35,000 feet do not get optics above the obscuring effects of the atmosphere. Similarly, there is no way to sample the atmosphere at 150,000 feet from a parabolic flight at 35,000 feet.
Numeric measurement is the foundation of science. I do not know where you got the idea that these flights were one hundred thousand dollars apiece. The published prices for tourist flights on Virgin Galactic and XCOR are in the public domain, at $200,000 and $95,000 respectively. Alan Stern pointedly did not mention the price that Southwest Research Institute paid for them.
I can only speak for XCOR, but I can say with all confidence that XCOR's Lynx spacecraft is designed to be a mature transportation system, that is, the marginal cost of flight is a single-digit multiple of the propellant cost. The Lynx burns about 3 tons per flight, about three quarters of which is dirt cheap liquid oxygen, during the flight at a total cost of $.16 a pound. The first half-dozen flights will be the most expensive ones, later flights will asymptotically approach the marginal cost.
The greatest benefit of suborbital flight, is not so much the tourist experience or the science that can be done, it is the opportunity for capable companies to mature a space transportation system so that the cost of orbital flight is also a single-digit multiple of propellant cost. Such a reduction in cost to low Earth orbit makes a huge number of things possible that are now impossible economically. Things like satellite solar power, a robust capability to deflect asteroids, and the possibility of supplying platinum group metals to the terrestrial economy.
Best regards,
Dr. Lee Valentine,
Director, XCOR Aerospace

Of course he’s right – some experiments can be done in suborbital flights that can’t be accomplished on a parabolic flight in the atmosphere. One of the perils of blogging is concision. I replied, in part:

Thank you so much for writing! You've sent a much more thoughtful response than my brief thoughts deserved, to be sure.
I think you're entirely right -- there are some experiments for which suborbital flights are the best approach going in the near future, and the cost is now at a point where grant dollars make them a credible expense. I mentioned that briefly but should have given it more attention.
Of course, that's a lot of money compared to my work...
As you write, the main benefit is in the long-term reduction of cost to low Earth orbit. If science institutes help pull the load for the first few dozen flights, it's certainly good all around. I wish that the press had dug more deeply into the cost/benefit curve and highlighted particular projects, which would clarify matters.

A few years ago, I had the extraordinary opportunity to speak at the IEEE Aerospace Conference. Like any kind of science, there is some amazing stuff and incredibly clever people. My regular readers probably have a good indication that I’m a real space buff – sort of the romantic, born-before-Apollo-ended type. I find the distant past so interesting because it tells us where we are going.