Suggestion for New Competition

In another forum, some particpants and spectators at the Xprize Cup, said they were so impressed by the sight of Pixel hoveribg at 50m, that they would love to see an "air time" or "hang time" competition.

I think this is a great idea. The basic rules could be:

1) The vehicles have to take off vertically.

2) The vehicles have to maintain a hover between 50m & 100m for as long as possible.

3) The vehicles have to land vertically.

4) The vehicles must operate under rocket power without aerodynamic lift.

5) The longest contiguous hover time is the winner. Second & third prizes should also be awarded.

There should be a regular competition witha minimum standard of 2 minutes and reasonable prizes, and a major prize for the first team to excede 17 minutes.

Note: A hover time of 16 to 17 minutes in 1 G is equivalent to the delta V required to reach Low Earth Orbit.

17 minutes of hovering in a single stage (so without dropping anything) and without aerodynamic assistance and not in vacuum, would be quite insanely hard, more likely indicatative of some form of divine intervention or cheating than anything else.
That said I like the general premise. What I'd really like to see is rocket vehicles attempting to navigate an obstacle course at high speed.

Yeah, 14 or 15 minutes may be more realistic for a near sea level air density approximation of SSTO delta V. But given an equivalent delta V, it should be slightly easier than SSTO, since you don't have to deal with a lot of issues.

Dropping anything could be negotiable. I quite like the idea of drop tanks (with parachutes). Engines should definitely not be dropped since we're trying to approach SSTO performance, not multiple stages. And stage separation at 50m might get a bit too exciting.

I doubt anyone would break 8 minutes for the first couple of years, unless the prizes were really big.

Wouldn't it be cool to have a 'meet' every 2 or 3 months at different locations for teams to try out their latest mods. There could even be a gantry with an adjustable tether, so teams don't have to get a permit.

No no no.... What is need for X-prize is a new competition.
Which team, can come up with the highest number of concepts and
iterations of there vehicles, I see two front runners right now.Starchaser MK? and Dreamspace Group Golden Palace.com Powered by the Da Vinci Projects Captain Canada.

Seriously though. Some kind of a propulsion contest might be cool, you know big thunder. Go BIG or Go Home!

How about best power to weight ratio for different classes of engine or highest isp for given propellants?

A team would not have to produce a huge engine just an efficient light weight one.

A hang time competition would encourage both of those. Nothing says the vehicle has to be large, but I suspect larger vehicles would have an advantage.

Maybe there should be 2 weight classes? MTOW above & below 1000kg?

I think hang time is a much better metric than pure ISP or thrust to weight, though the very deep throttling requirements that come with very long hang times certainly aren't ideal.

http://media.armadilloaerospace.com/misc/hppa2.htm

I don't know if this is still being offered, but it served its purpose and is still unclaimed.

I would guess that it is a lot easier to do an engine burn on a test stand compared to actually flying a vehicle. With the problems that Armadillo had with getting clearance I think it much more reasonable for teams to turn up with an engine which they connect up to a defined test stand.

You could even have a series of stands so that engines could fire simultaneously with the winner being the last one still running.

I think that doing the above breaks the task down into a more manageble segment and would allow more people to compete, also having a hovering vehicle is to much like the lunar lander challenge IMO.

An engine competition or series of competitions definitely has merit as an entry point, and to add some more excitement to an event like the XPC.

IMO, however, an engine test is not one tenth as exciting as a watching a VTVL hover. The less well informed among the spectators won't understand the engine technicalities like ISP, mdot, total impulse and mass ratio. They'll just like the noise and flames.

They would love rockets balancing on flame, with a huge timing clock and maybe a % of 'distance' to orbit display. And the odd spectacular crash.

At every event there would be a winner and a possibility of a new record, and for the runners up, anticipation of improving at the next event. It wouldn't be all or nothing like the LLC.

AST permits are a problem, but as Armadillo have shown, not an insurmountable one.

You know those big Sky Swing/Bungie Jump things they have at amusement parks? Those would be perfect for tethered flights. They are a couple hundred feet tall and can have very large spacing.

Having a large gantry like that would probably not be very expensive and would make testing and demonstrations very easy.