Nasa has requested an increase of more than $500m in budgetary allocation to $18.5bn during the fiscal year of 2016, to support the agency’s space exploration programmes.

Nasa administrator Charles Bolden said: "Nasa is firmly on a journey to Mars. Make no mistake, this journey will help guide and define our generation."

Mr Bolden said the additional allocation will help the agency in further developing the Orion crew vehicle, Space Launch System (SLS) and Exploration Ground Systems that will send astronauts beyond low-Earth orbit.

Nasa is currently developing the powerful SLS, which is a new heavy-lift rocket capable of sending humans aboard Orion to deep-space destinations such as an asteroid and Mars.

"Nasa is currently developing the powerful SLS, which is a new heavy-lift rocket capable of sending humans aboard Orion to deep-space destinations such as an asteroid and Mars."

Mr Bolden said: "The Orion spacecraft that recently performed a near flawless flight test on its first journey to space is being dismantled right now so it can reveal its secrets about that amazing flight."

"What we learn will prepare us for its next launch aboard our Space Launch System rocket, and its future with astronauts aboard exploring farther into our solar system than ever before."

The $2.5bn programme is preparing to conduct the rocket’s test flight in November 2018, according to Reuters.

In addition, the agency is seeking a 50% increase in allocation for a space taxi programme to $1.24bn, which is being developed by two private companies to transport astronauts to the International Space Station.

Nasa chief financial officer David Radzanowski was quoted by Reuters saying that if the funds are not allocated, the agency will not be able to meet the milestones.

The 2016 budget proposal also seeks funding for the James Webb Space Telescope programme, which is planned for launch in 2018, as well as for a potential future mission to Jupiter’s moon Europa.