Search results

Thanks for that. Ultra cool. Bob Clark

Amateurs have launched liquid-fueled rockets but their performance has been limited, as for example measured by their altitude reached. I get from that they are technically more difficult than solids. But they can get higher Isp than solids. For instance an upper stage kerosene rocket might be...

The earliest U.S. rocket to orbit that launched the satellite Explorer 1 did not use active guidance but spin stabilization. This meant it could not be put in a precise orbit. Later developments allowed active guidance to be used to deliver payloads to precise orbits. If an amateur team can...

These amateurs achieved at least 0.7 propellant fraction with small motors: https://www.rocketryforum.com/threads/orbital-space-is-25-times-harder-than-suborbital.175851/page-2#post-2351898 This amateur achieved 75% propellant fraction with a small motor and believes this could be raised 20%...

The SS-520 is in the 650 to 1 gross mass to payload range. So a 1 kg payload would be in the range of a 650 kg rocket. Amateurs have made 200 kg rockets, so 650 kg is conceivable. The Aerotech commercial motor K1103 does have a 290s vacuum Isp using their “Propellant X” formulation“ (fact...

Member, Neutronium95 noted that Aerotech M2050 has a 290+s vacuum Isp as modeled by OpenMotor: https://www.rocketryforum.com/threads/orbital-space-is-25-times-harder-than-suborbital.175851/ It turns out it uses a propellant formulation called "Propellant X" by Aerotech. If you search on...

By the way, I noticed even for rockets going supersonic and hypersonic OpenRocket has this odd quirk in that it will give higher altitude for short, squat nozzles, compared to long, pointed ones. See if you can get a higher altitude from OpenRocket using a short ogive nozzle. Bob Clark

The page is no longer active. It appears to have been competing for the Google Lunar X-Prize for which a private team would send a robot rover to the Moon and send back high-def video. The prize went unclaimed. I think that prize was too ambitious. Instead, what should be proposed is a prize for...

😏

We should all remember the famous statement of Albert Einstein, “I know not with what weapons World War III will be fought, but World War IV will be fought with sticks and stones." Bob Clark

Could you post the OpenRocket sim so we can confirm this altitude? About the active guidance, amateur Joe Bernard was able to do engine gimbaling on a rocket: This would not need spin-stabilization. But this is at relatively slow speed. I imagine it would be a more difficult proposition at...

Ok. If you’re making the argument that advanced amateurs can use straight-off-the-shelf motors with staging and without the added complexity of doing it without airframes can still reach the von Karman line, then I’ll accept your argument. 😁 Bob Clark

Commercial solid rockets commonly get 280+s vacuum Isp: But for a particular propellant combination, vacuum Isp is largely a matter of nozzle size. So for the upper stages we can get higher vacuum Isp for our motors using longer nozzles. This will increase the payload possible. This is why...

??? Like Sheldon on “The Big Bang Theory” I have been accused of being irony impaired. Can’t tell if that is a serious question or not. ”Bob” is a well-known nickname for Robert. Robert Clark

Thanks. What’s the final payload that reaches orbit? Bob Clark

Definition: To be “bobclarked”: to be led to a surprising and unexpected or even counterintuitive conclusion by force of logic alone. 😉 Bob Clark

Actually, the university teams are operating like that. Remember these are not for profit efforts. They are educational efforts. It is these educational efforts I’m arguing can make advancements in science because of the sheer numbers of rockets that can be sent to space and even on...

SpaceX was able to show it is possible to literally cut 90% off the development cost of an orbital rocket. Now imagine a scenario where you literally have zero labor costs, using university students willing to work for pizza during lunch breaks and college credits? Bob Clark

Thanks for the image of the Lambda 4S trajectory. Openrocket and RasAero can’t do orbital trajectory sims because they can’t model first launching vertically, then doing a pitch over to a specified angle at a specified altitude. However, they can model launching at a specified angle to begin...

In the professional industry, for suborbital sounding rockets and for orbital rockets, airframes, i.e., body tubes, aren’t used because they add unneeded extra weight, where minimizing weight is paramount. I think using body tubes is a holdover from the old Estes rockets days where you placed...