MAI suggested using lighter launch vehicles

Scientists of Moscow Aviation Institute (MAI) offer to upgrade launch vehicles to a light class through the use of upper stage with solar thermal rocket engines. They have greater capacity than standard units, says the report that scientists are going to present to the Academic Conference on Astronautics.

— It is of the possible solutions to this problem and increasing the efficiency of the design-ballistic of upper stage. Ballistic efficiency of it is 1,5-2 times higher than the possibility of liquid funds for inter-orbit transportation. It is possible to use rockets more lightweight class, — stated in the listing.

It is noted that these upper stages will have a specific impulse of 700-900 seconds at a thrust of 200 newtons. Due to these indicators energetically favorable multi-pulse scheme for the removal of spacecraft into geostationary orbit can be used.

Scientists believe that the launch time should be about 30-60 days. A further increase in time will be impossible to increase the weight of the payload.

Engines offered by scientists are made on a “concentrator-receiver”. This scheme allows heating the working fluid (hydrogen) to 2500-2900 degrees Celsius due to which the highest specific impulse is provided, compared to all similar projects.

It is noted that the development of upper stage with “solar” engine paired with certain technological difficulties. In this case the task of launch ascent fails as it can’t be divided into dynamic and parametric components. Developers will have to optimize the parameters of the spacecraft, propulsion and flight path with a time limit for removal and the size of the concentrators.