Dr Maggie Aderin-Pocock, who tours inner-city schools urging pupils to study science, said students with passion can overcome any obstacles.
She has won a Women In Film And TV award for her work presenting BBC2's Do We Really Need the Moon?
The 43-year-old, who has a daughter aged two, has spoken to 100,000 children in the last year to bust stereotypes about science.
She said: "I go to London schools where pupils may be disillusioned and tell them to find something they have a passion for. If you enjoy the subject it's so much easier to learn.
"Many kids think, 'I have had a slow start in life, my parents have broken up and I have dyslexia'. But I say even if things don't look rosy for you now, that can turn around.
I tell them to have a dream: it can take you very far. But you have to study to fulfil that dream." Dr Pocock was diagnosed with dyslexia at school and "shunted into remedial classes".
It was not until she discovered science at the age of 10 that she became passionate about schoolwork.
"The dyslexia does not go away, but I have found ways of working around it," she said. "In space science I attend international delegations where I have to write onto a screen and everything comes up in big letters.
Sometimes people say, 'You don't spell that word like that.' But I like to be open about my dyslexia so people understand.
"The most important thing is to not give up because you can't spell."
Dr Pocock is the lead scientist at British space technology company Astrium. She is helping to develop the mid- infrared instrument for the James Webb space telescope, which will orbit earth, peering into deep space to discover secrets of the birth of the universe.
She added that some girls still think science is for boys, and when she first told a teacher she wanted to be an astronaut, it was suggested she try nursing "as that was science too".
She said: "There are not that many women and not many black women in science. We aren't doing a good job getting people into science - we need to get it to everybody. Many girls think it's boys' stuff. I am trying to say it's a wonderful subject."
Dr Pocock went to La Sainte Union convent school in Camden, gained A-levels in maths, physics, chemistry and biology, and did a degree in physics and a doctorate in mechanical engineering at Imperial College London.