Gerstenmaier also said that NASA is exploring Moon missions, including establishing a base on Earth's satellite.
On March 21, President Donald Trump issued a mandate for the agency to get people to Mars by the 2030s, and within a week, NASA came up with a detailed plan for landing a human on the Red Planet.
He added there's just about two percent increase in the budget levels and they now lack surface systems for Mars as landing on the Martian soil is a huge challenge. "I can't put a date on humans on Mars, and the reason really is.at the budget levels we described, this roughly two percent increase, we don't have the surface systems available for Mars", said William Gerstenmaier, Nasa's chief of human spaceflight, this week, Ars Technica reports. Now it is working to outfit a Dragon spacecraft that may land on the Red Planet in 2020.
NASA's Orion spacecraft was scheduled to make its first flight into space in 2018, but the funding challenges have forced the agency to push back the mission to 2019. In the case of NASA, the agency recently admitted during a meeting that even landing on Mars is beyond them.
French President pays tribute to Nice victims
A group representing the families of victims had complained that the magazine was being insensitive for "morbid sensationalism". The ruling, made late on Thursday, came after the Paris prosecutor called for the magazine to be removed from sale.
Lynda Carter says she discussed a role in 'Wonder Woman' sequel
She called the story was "entirely false" and said it was made up by someone trying to " spread some serious misinfo ". Fighting alongside men in a war to end all wars, she finally discovers her full powers and true destiny.
Vanguard names new chief exec
Vanguard , based in Malvern, Pa., is one of the world's biggest fund managers, with $4.4 trillion in assets. Vanguard saw global inflows of $289bn in 2016 - more than the rest of the industry combined.
As a United States government organization funded by the taxpayers, one would think that NASA is one of the most well-funded bodies in the world.
Meanwhile, Gerstenmaier was more welcome to the idea of NASA contributing to the establishment of a lunar base.
"If we find out that there is water on the Moon and we want to do more extensive human operations on the Moon to explore that, we have the ability with Deep Space Gateway to support an extensive Moon surface program", he added.
It is timely however that given recent developments, it would appear that private space companies are likely to play a key role - if not shape - the future of space exploration.